PurposeThis study aims to evaluate the impact of the proposed CARICOM Octagon “High In” Warning Label (OWL), against four alternative Front-of-Package Nutrition Labels (FOPNLs): US “Facts Up Front” (FUF), UK Multi-Traffic Light (MTL), Mexican OWL and the Brazilian Magnifying Glass “High In” Warning Label, on respondents’ purchase intentions, perception of healthiness and understanding of nutritional information across and within food products.Design/methodology/approachIn an online randomized control experiment, adults from eight CARICOM countries (n = 948) were randomly assigned to a control and four treatment FOPNL groups. Respondents were tasked to choose between four categories of mock products with three variations in healthfulness across and within products.FindingsNo statistically significant difference (p > 0.05) was found across FOPNL groups compared to the OWL on outcomes of purchase intentions and perception of healthfulness. Regarding the understanding of nutritional information, FUF performed the best, as participants were 1.76 times (p = 0.03) and 3.23 times (p = 0.00) more likely to correctly identify the products with the highest and lowest amount of sugar, respectively. Results were similar for products with the lowest sodium (odds ratio [OR] = 2.25, p = 0.00) and highest saturated fats (OR = 2.11, p = 0.00).Research limitations/implicationsSome limitations of this study include the use of an online platform to conduct the experiment. Though this was the most cost-effective method of execution and presented many benefits, there were limitations to using this approach. Firstly, this approach may not entirely replicate the real world in store purchasing settings. Although online grocery shopping is becoming increasingly popular, in the Caribbean, most grocery purchases are made in stores. Furthermore, online surveys are more likely to lead to samples with higher educational and income levels than the average population (Bethlehem, 2010). The skewedness observed was not unique to this study and was common with similar published studies (Franco-Arellano et al., 2020; Packer et al., 2021; Talati et al., 2018). Nevertheless, all respondents were randomly assigned to groups, and it was confirmed that there were no systematic differences in the education and income levels of participants across the FOPNL groups.Practical implicationsSome CARICOM policy makers advocate for the use of “High In” warning labels to limit the intake of nutrients of concern (NOCs) and to encourage healthier eating habits among consumers. However, regional private sector stakeholders have expressed concern about the lack of sufficient research undertaken at a regional level, to inform the effectiveness of this model within CARICOM, and some have also expressed a preference for the use of other interpretative and reductive FOPNLs, already in use in the Region. The results of this study reveal that while interpretative FOPNLs like the Draft CARICOM Regional Standard, DCRS5 (OWL) can assist consumers in making healthier purchase decisions, it was outperformed by the MTL on perception of healthiness and by the FUF on the understanding of nutrient information. It was also noted that the DCRS5 (OWL) was more effective when choosing across products with distinct nutritional differences but performed poorly in assisting respondents with making healthy purchasing decisions when all the products contained NOCs above the relevant thresholds. This study’s findings highlight that the existing FOPNL schemes can be further enhanced for improved outcomes. This can be achieved by using a hybrid approach which includes both reductive and interpretative elements to allow for comparison across and within food products. The literature also suggests the use of colour and combining positive as well as negative elements to encourage ease of interpretation, improved understanding and healthier food choices.Social implicationsA properly designed FOPNL can support consumers in making healthier food choices; however, it must be accompanied by measures to raise consumer awareness and increase the health literacy of the population to cause shifts in preferences and behavioural patterns over time. This must also be coupled with policies to make healthy food choices more affordable to the general population.Originality/valueThe results of this study revealed that FUF and MTL performed the best in assisting participants to correctly identify between products with the highest or lowest NOCs at the 5% significant level, and that the OWL performed poorly in assisting participants with making healthy purchasing decisions when all the products contained NOCs above the relevant thresholds.